DRAGON88

I was wondering if it would be good to run race fuel through the car every now and then to persay clean it out... I usually run either 89 or 91 oct, but what about running 100 oct fuel every 6 months or so? If I understand correctly doesnt europe get better fuel than in the states (oct wise). I allways figured that beacause of how much more "petrol" is over the pond, it must be higher octane, and the government must tax it more too. thoughts, oppinions?

PxTx

Higher octane = slower burn rate. That is why you can eliminate ignition pinging with it. Think of the flame front as it pushes accross the piston. If the burning fuel runs out before it is finished pushing the piston, you get that pining noise.

No, running higher octane fuel, when it is not nessisary will do just the opposite of "cleaning things out".

Paul T

PJM99

I wouldn't recommend using nothing higher than 93 Octane. Higher octane = slower burning and is designed for cars with higher compression or non-N/A because the engine make enough pressure to explode the fuel in the combustion chambers fast enought to turn things. Lower octanes burns faster and are best used in lower compression engines because they need that faster burn to turn things. If you put high octane fuel into a low compression motor you will excess unburned fuel which will gunk things up inside your engine.

My Cobra for example runs about 9.5 to 1 compression now. Anything under 91 oct and she pings. This is because you have a faster burning fuel inside a high compression engine throwing things off balance.

The Audi can pretty much run on anything we see at the pumps. I use 89-93 octanes regularly. But in my truck I use 87 because that is what is suggested by Dodge. They say higher octane will actually damage the engine over time.

Octane is not the clean rating of the engine, it more of the burn rate if you will. High octane= slow burn, low octane = fast burn

DRAGON88

thanks, that makes alot of sense.